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ARC102B . Moisture protection Protection of materials Lumber & other products Framing the house. Review. How many divisions are there in a set of specifications? 49 Concrete strength is measured in what type of units? MPA ( megapascal )
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ARC102B Moisture protection Protection of materials Lumber & other products Framing the house
Review • How many divisions are there in a set of specifications? • 49 • Concrete strength is measured in what type of units? • MPA ( megapascal ) • What is the minimum strength for concrete exposed to the environment? • 32 mpa with air entrainment
Review • Which type of concrete trowel will give you a smooth finish? • steel • Concrete footings should project a minimum of how many inches past the foundation wall? • 4” • Name 4 common types of materials used in foundation wall construction. • poured concrete, masonry block, preserved wood, precast concrete
Review • After pouring a concrete foundation wall, what should be inserted in the concrete before it starts to cure? • anchor bolts • What is the nominal size of a 10” concrete block? ( W x H x L ) • 10” x 8” x 16” • How much smaller is a concrete block from it’s nominal size? • 3/8”
Foundation dampproofing and water proofing page 65 • Dampproofing is required by all foundation walls that are part of a basement • Used to control the movement of moisture • Water-proofing is required only for foundations that are subject to hydrostatic pressures.
Foundation dampproofing • Dampproofing types • heavy coat of bituminous material (rolled, brushed or sprayed tar) • polyethylene sheet material • rubberized membrane (sprayed blue, green) • Drainage blankets are attached to the foundation walls after dampproofing to help in moving moisture to drainage tiles located at the footings.
Foundation drainage page 66 • First part of drainage is to slope ground away from the building • Perforated tile is installed on the outside of the footing on firm soil to help carry excess water away from the foundation • 6” minimum of clear gravel must cover the drainage tile which acts as a filter.
Foundation drainage • Drainage tile is connected to the storm sewers at the road • In areas of very wet sites, drainage tile will be installed along the inside of the footing and possibly laterally under the slab to prevent hydrostatic pressures.
Backfilling page 68 • Backfilling foundation walls should not be carried out until the floor joists and subfloor are in place • Backfilling material should be clean of construction waste • Uniform backfilling is necessary to prevent damage such as cracking in the walls.
Foundation insulation page 70 • Foundations can be insulated on the interior or exterior • Foundation walls must be insulated a minimum of 24” below finished grade • Interior insulation usually requires installing framing to support the insulation • Exterior insulation reduces the temperature swing which reduces thermal stress & cracking.
Footings & foundations for crawl spaces page 70 • The principal is the same except that the excavation is only a trench • There is no dampproofing required • Usually no concrete slab but the ground is covered with a 6 mil polyethylene sheet • The crawl space must be vented.
Protection & care of materials page 75 • taking care of job site materials will prevent wastage and troublesome construction defects • materials should be shipped to the site just before it is to be used • all materials should be placed on skids raised off the ground and covered to shed water
Protection & care of materials • as the framing is being constructed, it is very hard to protect material until the roof , windows and doors are in place • any materials that are exposed to moisture usually dry quickly during spring, summer and fall • insulation, wall and ceiling finish can be stored in the house • CAUTION with drywall stacked at one location for a prolonged period of time
Protection & care of materials • hardwood flooring, interior trim and millwork should not be on site until basement slab is in place and if possible the HVAC system is up and running
Lumber page 79 • most residential projects use dimension lumber 1 ½” to 3 ½” thick and 1 ½” to 11 ¼” • see page 364 for actual sizes of lumber Grades • grade markings are used to show that it conforms to the ( NLGA ) National Lumber Grades Authority & to CSA Standard 0141, Softwood Lumber
Grade Marks • Display • name or symbol of agency • species • grade • moisture content • mill number • see page 360
Grade • based on physical characteristics each piece of lumber is examined and assigned a grade • Select Structural is the highest quality available, where high strength, stiffness and good appearance are required • No 1 grade has larger knots but, still the high strength and stiffness of select structural • No 1 & 2 grades, are popular for most general construction uses
Grade • No 3 grade is used where appearance is not a factor • Stud grade is stiff, straight suitable for vertical wall members and also has the following grades: • construction • standard • utility • economy
EWP page 80 • Engineered Wood Products provide equivalent or better performance to dimension lumber • EWP uses less wood from small trees, which make better use of forest resources • Some of the EWP products are: • glue-laminated beams • wood I-joists • structural composite lumber
EWP • dimension lumber & wood products are often combined with glue or mechanical fasteners to produce EWP ( see page 81 ) • structural composite lumber consists of: • thin veneer strips or panels • waterproof adhesive • bonded by heat and pressure
Sheet or Panel Products • Plywood • multiple thin plies of wood running in opposite direction glued together • thickness range from 1/4” to 3/4” • exterior grade plywood has a different type of glue • Waferboard, Oriented Strand Board ( OSB ), Fiberboard, Particleboard and Hardboard
Framing the house page 85 • structural shell consists of the foundation, floors, walls, roof and some interior load bearing walls ( see diagram page 85 ) • the shell must be framed and sheathed to obtain its rigidity
Framing types • Two types of framing • platform • balloon • Platform • most common • floor system is built independently from the walls • studs are one storey • bottom & top plates provide a firestop at floor and ceiling and nailing support
Framing types • Balloon • rarely used • studs are continuous from foundation to roof • floor framing is installed after walls are built
Assignment • All releases for visual project are due • Work on your visual project • Canadian Wood-Frame House Construction book mandatory for next week • Read pages 91 to 108